Procedure and Discussion of Failure Analysis in Iron-Steel Materials

2014 ◽  
Vol 556-562 ◽  
pp. 261-264
Author(s):  
Zhi Gang Wang ◽  
Lu Dan Shi ◽  
Min Jing ◽  
Yong Xu
Keyword(s):  
Failure Analysis ◽  
Hot Forging ◽  
High Hardness ◽  
Optical Microscope ◽  
Metallographic Analysis ◽  
Good Teaching ◽  
H13 Steel ◽  
Quenching Temperature ◽  
Scan Electronic Microscope ◽  
Electronic Microscope

The failure analysis of the H13 steel hot-forging mould is the main content in the open experiment. The scan electronic microscope and the optical microscope are used to analyze the failure workpiece in this experiment. The over-high quenching temperature, the too low drawing temperature, the insufficient drawing time and frequency, the over-high hardness value are the main reasons of fracture failure of the mould. The work environment of the failure materials, the heat treatment processing, the metallographic analysis, the fracture analysis and the using of test standard are the important aspects which the students should know. The students can learn how to analyze problem and how to solve them from the open experiments which is a good teaching try.

The Research on the Microstructure and Property of Gear with Sinter Powder Material

2010 ◽  
Vol 37-38 ◽  
pp. 1558-1560 ◽  
Author(s):  
Bai Yang Lou ◽  
Fang Liang Dong ◽  
Bin Xu
Keyword(s):  
Powder Material ◽  
Base Material ◽  
Residual Austenite ◽  
Optical Microscope ◽  
Micro Hardness ◽  
Tempered Martensite ◽  
Common Part ◽  
Energy Spectrometer ◽  
Scan Electronic Microscope ◽  
Electronic Microscope

Gear is a widely used common part of machinery, which is of good lubricate property and low materials consumption when it is made of sinter powder material. In this paper, the chemical composition, microstructure and property of sintered gear were investigated with optical microscope, scan electronic microscope, micro hardness meter and X-diffraction energy spectrometer. The results show that the microstructure of the gear includes of tempered martensite, carbide, residual austenite and a small quantity of cavity. The distribution of iron element is even. The copper and nickel distribute unevenly and cover around the surface of carbide in gear material which makes different property of covered layer itself between carbide and base material. The existing of covered layer and weak grain-boundary strength are main reason for gear brittle fracture. The gear’s toughness can be increased by optimizing sintering technology and heat treatment.

Failure Analysis and Strengthening Method for Circular Diamond Saw Blade

2010 ◽  
Vol 152-153 ◽  
pp. 1616-1619
Author(s):  
Bai Yang Lou ◽  
Pei Hua Li ◽  
Le Guo Li
Keyword(s):  
Wear Resistance ◽  
Optical Microscope ◽  
Wear Coefficient ◽  
Diamond Saw ◽  
Enhance Wear Resistance ◽  
Saw Blade ◽  
Scan Electronic Microscope ◽  
Energy Disperse Spectroscopy ◽  
Electronic Microscope ◽  
Strengthening Method

The main causes of segment failure of diamond saw blade are studied in this paper. The segment material, the microstructure and the wear resistance of saw blade material were studied with scan electronic microscope, energy disperse spectroscopy, hardness meter, optical microscope. The results shows that the addition of alloying elements could refine grains, improve the holding force of matrix to diamond, enhance wear resistance of matrix to diamond, and decrease wear coefficient about 20%.

Fatigue Failure Analysis on Key Components of Bladder Accumulators

2015 ◽  
Vol 750 ◽  
pp. 363-370
Author(s):  
Ya Ping Niu ◽  
Bing Bing Chen
Keyword(s):  
Failure Analysis ◽  
Fatigue Failure ◽  
High Stress ◽  
Peak Stress ◽  
Optical Microscope ◽  
Metallographic Analysis ◽  
The Finite Element Method ◽  
Valve Body ◽  
Support Ring ◽  
Initiation And Propagation

Fatigue failure analysis on key components of bladder accumulators was conducted. Failure fracture of the key components, which included the shell, the support ring and the oil inlet valve body in the accumulators, was investigated by optical microscope (OM) scanning electron microscope (SEM). According to the metallographic analysis and micro-hardness determination at the crack profile, crack initiation and propagation direction was confirmed. By simulation using the finite element method, it was detected that the peak stress of the key components applied on the contact surfaces. Obvious plastic deformation was observed at the region with high stress. However, the fatigue crack did not initiate at the contact surface, but occurred on the second high stress area without contact.

Failure analysis of H13 steel die for high pressure die casting Al alloy

2021 ◽  
pp. 105330
Author(s):  
Rengen Ding ◽  
Haibo Yang ◽  
Shuzhi Li ◽  
Guodong Wu ◽  
Jiahao Mo ◽  
...  
Keyword(s):  
High Pressure ◽  
Failure Analysis ◽  
Die Casting ◽  
Al Alloy ◽  
H13 Steel ◽  
High Pressure Die Casting ◽  
Pressure Die Casting

Failure Analysis of Hydrogen Corrosion of the Lens Gasket

2010 ◽  
Vol 37-38 ◽  
pp. 462-465
Author(s):  
Xiao Chun Ma ◽  
Guang Fei Xu
Keyword(s):  
High Pressure ◽  
Failure Analysis ◽  
Intergranular Crack ◽  
Optical Microscope ◽  
Corrosion Characteristic ◽  
Hydrogen Corrosion ◽  
Corrosion Depth ◽  
Fertilizer Plant ◽  
Inner Surface ◽  
Hydrogen Blister

The 10MoWVNb steel lens gaskets are widely used for the flange linking of high pressure tube in the synthetic ammonia system in chemical fertilizer plant. The gasket worked in H2-N2-NH3 environment at the temperature of 300°C. It often fails because of hydrogen corrosion. The microstructure and corrosion characteristic of the lens gasket were studied by optical microscope. The results showed that the hydrogen blister appeared preferentially at the interface of inclusions. The corrosion depth was 0.65 millimeter. There were little intergranular crack on inner surface.

Microstructure and Hardness of Ni-Cr Porous Preform Reinforced Al-Based Composites by Low Infiltration Method

2011 ◽  
Vol 275 ◽  
pp. 251-254
Author(s):  
Hua Wei Rong ◽  
Cheol Hong Park ◽  
Won Jo Park ◽  
Han Ki Yoon
Keyword(s):  
Intermetallic Compounds ◽  
Rapid Development ◽  
High Hardness ◽  
Optical Microscope ◽  
Matrix Composites ◽  
X Ray Diffraction ◽  
Infiltration Process ◽  
Pressure Infiltration ◽  
X Ray ◽  
Infiltration Method

With the rapid development of aerospace and automobile industries, metal matrix composites (MMCs) have attracted much attention because of its excellent performance. In this paper, Ni-Cr/AC8A composites reinforced with porous Ni-Cr preform were manufactured by low pressure infiltration process, infiltration temperatures are 700oC~850oC. The microstructure and phase composition of composites were evaluated using optical microscope, X-ray diffraction (XRD) and electro-probe microanalysis (EPMA), It's found that they're intermetallic compounds generated in the composites. Recently, intermetallic compounds have attracted much attention as high-temperature material. We study the hardness of Ni-Cr/AC8A composites, the results show the Ni-Cr/AC8A composite has high hardness due to the intermetallic compounds exist.

Appraisal on corrosion performances of CrNi, TiAlN/CrNi and CrNi–Al2O3–TiO2 coatings on H13 hot work mold

2020 ◽  
Vol 67 (2) ◽  
pp. 150-157
Author(s):  
Kong Dejun ◽  
Li Jiahong
Keyword(s):  
Corrosion Resistance ◽  
Salt Spray ◽  
Test Chamber ◽  
Electrochemical Corrosion ◽  
Optical Microscope ◽  
Electrochemical Performances ◽  
X Ray Diffraction ◽  
H13 Steel ◽  
Content Type ◽  
Electrochemical Corrosion Resistance

Purpose The purpose of this paper is to evaluate the salt spray corrosion (SSC) and electrochemical corrosion performances of CrNi, TiAlN/NiCr and CrNi–Al2O3–TiO2 coatings on H13 steel, which improved the corrosion resistance of H13 hot work mold. Design/methodology/approach CrNi, TiAlN/NiCr and CrNi–Al2O3–TiO2 coatings were fabricated on H13 hot work mold steel using a laser cladding and cathodic arc ion plating. The SSC and electrochemical performances of obtained coatings were investigated using a corrosion test chamber and electrochemical workstation, respectively. The corrosion morphologies, microstructure and phases were analyzed using an electron scanning microscope, optical microscope and X-ray diffraction, respectively, and the mechanisms of corrosion resistance were also discussed. Findings The CrNi coating is penetrated by corrosion media, producing the oxide of Fe3O4 on the coating surface; and the TiAlN coating is corroded to enter into the CrNi coating, forming the oxides of TiO and NiO, the mechanism is pitting corrosion, whereas the CrNi–Al2O3–TiO2 coating is not penetrated, with no oxides, showing the highest SSC resistance among the three kinds of coatings. The corrosion potential of CrNi coating, TiAlN/CrNi and CrNi–Al2O3–TiO2 coatings was –0.444, –0.481 and –0.334 V, respectively, and the corresponding polarization resistances were 3,074, 2,425 and 86,648 cm2, respectively. The electrochemical corrosion resistance of CrNi–Al2O3–TiO2 coating is the highest, which is enhanced by the additions of Al2O3 and TiO2. Originality/value The CrNi, TiAlN/CrNi and CrNi–Al2O3–TiO2 coatings on H13 hot work mold were firstly evaluated by the SSC and electrochemical performances.

Torque Converter Turboshaft Fracture Failure Analysis and Improvement

2014 ◽  
Vol 571-572 ◽  
pp. 1087-1090
Author(s):  
Lei Zhang ◽  
Xi Bao Chen ◽  
Hong Bo Shan ◽  
Xue Lei Wu ◽  
Yan Min Zhao
Keyword(s):  
Electron Microscopy ◽  
Failure Analysis ◽  
Torque Converter ◽  
Optical Microscope ◽  
Mechanical Transmission ◽  
Transmission Power ◽  
Improvement Program ◽  
Fracture Failure ◽  
Cause Of Failure ◽  
Scanning Electron

Torque converter turboshaft is a hydraulic mechanical transmission devices of key components. In a new-mounted hydraulic mechanical transmission, super heavy laden vehicle during the test, the torque converter turboshaft fracture occurs when the vehicle traveling to 13 00 km, resulting in transmission power interruption, chassis parking problems. To achieve accurate positioning of the torque converter turboshaft fracture failure reasons, this paper analyzes the means of optical microscope and scanning electron microscopy, carried out on the fracture failure analysis, then using classical and finite element method to calculate the turboshaft intensity of the strength, and proposed optimization improvement program based on the cause of failure.

Vehicle Driving Axle Half Shaft Fracture Analysis

2014 ◽  
Vol 912-914 ◽  
pp. 658-661
Author(s):  
Jun Jie Wang
Keyword(s):  
Electron Microscope ◽  
Fatigue Strength ◽  
Shaft Fracture ◽  
Fracture Analysis ◽  
Optical Microscope ◽  
Automobile Driving ◽  
Quenching Temperature ◽  
Torsional Fatigue ◽  
Conditioning Treatment ◽  
Scanning Electron

by using optical microscope and scanning electron microscope (sem), for minitype automobile driving axle half shaft fracture piece of organization and the fracture characteristic is analyzed and the results show that the axle shaft of conditioning treatment in the quenching temperature high enough, make its surface and center organization exists in the group more ferrite, caused the artifacts of the final hardness and fatigue strength is insufficient, led to the use of half shaft torsional fatigue fracture.

A Study of Developing Composite Material of Penetrated Diamond Particles Into Metal Plate

2009 ◽  
Author(s):  
Keijiro Nishi ◽  
Shigeru Tanaka ◽  
Shigeru Itoh
Keyword(s):  
Thermal Conductivity ◽  
Shock Wave ◽  
Composite Material ◽  
High Speed ◽  
High Hardness ◽  
Optical Microscope ◽  
Metal Plate ◽  
Underwater Shock Wave ◽  
Diamond Particles ◽  
Underwater Shock

An explosive welding technique which uses underwater shock wave to weld thin aluminum plate has been studied and the technical advantages were reported. In this research, we propose a method to produce a composite material using an underwater shock wave generated by detonation of explosive. In the production process, a metal plate (flyer plate) accelerates to a high speed by the underwater shock wave, and collided with diamond particles and penetrated the metal plate. Diamonds were used as the particles and aluminum plates (A1050) as the flyer plates. Diamond has high hardness and excellent thermal conductivity, therefore diamond should provide improvement in the thermal conductivity of the composite material. From recovered sample, the multilayer joined surface including diamond particles was observed using an optical microscope. The production of the pipe of composite materials was attempted using this technique as the application. Details of the experimental methods and results are reported in this paper.

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